Screening Of Bacillus And Its Application In Compound Fertilizer

The amount of farmland ginseng planted increases year by year,but there is no standard for fertilizer application.Abuse of fertilizers and poor quality f ertilizers lead to a decline in the quality of ginseng,a decrease in yield,and a ggravation of diseases every year.Compound microbial fertilizer is of great sig nificance to increase ginseng output,improve ginseng quality,and develop gree n ginseng industry.In this study,we screened functional strains in the ginseng rhizosp Here soil,and explored the optimal conditions for the fermentation of compound strains through single factor experiments and orthogonal experiments.Combined with the screening results of carriers such as bacterial bran,bacteri al fertilizer was prepared,and the fertilizer effect of the bacterial fertilizer and the antagonistic effect of pathogenic bacteria were evaluated.The main conclu sions were as follows:(1)Through the isolation of ginseng rhizosp Here soil microorganisms,a to tal of 139 functional strains were isolated,including 45 strains of p Hosp Hate-s olving bacteria,64 strains of potassium-dissolving bacteria,and 30 strains of ni trogen-fixing bacteria,and 4 of them with strong activity were selected for the production of bacterial fertilizer.(2)The antagonism test showed that there was no antagonism between the four types of bacteria,and the ratio of the four types of bacteria could be mi xed to be 1: 1: 1: 1.According to the growth curve measurement,the time fo r the bacteria in the mixed culture to reach the logarithmic growth p Hase was6.67 hours earlier than the time for the bacteria cultured alone to reach the l ogarithmic growth p Hase,indicating that there was a synergistic effect between the four bacteria.(3)The single-factor test results show that sucrose was the most suitable carbon source for compound microorganism fermentation,and the most suitable nitrogen source for compound microorganism fermentation was beef extract.O rthogonal test results showed that the most suitable compound microbial fermen tation medium ratio is sucrose 0.5% + beef extract 1.5% + sodium dihydrogen p Hosp Hate 0.2% + disodium hydrogen p Hosp Hate 0.2%.When the culture te mperature was 30 ?,the rotation speed was 200 r / min,the initial inoculationamount was 3%,and the fermentation liquid was 125ml(250ml Erlenmeyer fl ask),the number of viable bacteria in the fermentation liquid of the compound strain could reach 6.67 × 109 CFU / ml.(4)The carrier screening test showed that the bacterial bran,biochar and diatomaceous earth were not toxic to the growth of the composite strain.Bacte rial bran had good water absorption,but the results of bacterial release rate an d bacterial survival time indicated that the bacterial bran was not suitable as a carrier for bacterial fertilizer.Diatomaceous earth had moderate water absorpti on capacity and high bacterial release rate.Using diatomite as a carrier could effectively extend the shelf life of bacterial fertilizer.(5)A fungus causing strawberry leaf spot disease was isolated from straw berries grown in a ginseng plantation protected area.According to morp Hology and molecular biology,it was identified as Fusarium oatum.This kind of lesi ons seriously affected strawberry yield and quality.(6)The bacterial fertilizer created in this study could effectively increase t he yield and drying rate of ginseng,and had a good control on ginseng rust r ot and root rot and strawberry leaf spot.In addition,this kind of bacterial ferti lizer had strong adaptability and obvious effect,and a small amount of dosage could achieve good disease prevention and yield increase effects.